This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A273807 #7 Sep 08 2022 08:46:17
%S A273807 431,443,683,65963,4294967723
%N A273807 Primes of the form 2^(2^n) + 427.
%C A273807 Terms given correspond to n = 1, 2, 3, 4 and 5.
%C A273807 Next term >= 2^2^27 + 427. - _Charles R Greathouse IV_, Jun 07 2016
%t A273807 Select[Table[2^(2^n) + 427, {n, 0, 15}], PrimeQ]
%o A273807 (Magma) [a: n in [0..16] | IsPrime(a) where a is 2^(2^n)+427];
%o A273807 (PARI) for(n=1,5, if(ispseudoprime(t=2^2^n+427), print1(t", "))) \\ _Charles R Greathouse IV_, Jun 07 2016
%Y A273807 Cf. similar sequences listed in A273547.
%K A273807 nonn
%O A273807 1,1
%A A273807 _Vincenzo Librandi_, Jun 02 2016